FXUS61 KILN 232359 AFDILN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 659 PM EST MON NOV 23 2009 .SYNOPSIS... A WEAK UPPER SHORTWAVE OVER THE OHIO VALLEY WILL MOVE EAST OF THE REGION THIS EVENING. A STRONGER UPPER TROUGH WILL DIG INTO THE MIDWEST ON TUESDAY AND WEDNESDAY...FOLLOWED BY AN EVEN DEEPER SYSTEM WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... WEAK DISTURBANCE CAN BE SEEN ON WV IMAGERY ROTATING INTO SOUTHERN OHIO. SHOWER ACTIVITY AHEAD OF THIS FEATURE HAS BEEN LIGHT AND SPOTTY...AND WILL CONTINUE TO PUSH EAST OF THE SCIOTO RIVER VALLEY THIS EVENING. SEEING LOW CLOUDS ERODE FAIRLY QUICKLY ACROSS THE WESTERN PORTIONS OF THE CWA...THOUGH A SECOND SURGE OF LOW LEVEL MOISTURE IS COMING IN FROM THE SOUTH. MODEL FORECAST SOUNDINGS SUGGEST QUITE A BIT OF LOW LEVEL MOISTURE BECOMING TRAPPED BENEATH A MODEST INVERSION TONIGHT...ESPECIALLY ACROSS THE WESTERN CWA WHERE CLOUDS ARE THINNING. WILL NEED TO WATCH THIS AREA FOR FOG DEVELOPMENT LATER TONIGHT. HOWEVER...MRI INDICATES POSSIBLY ENOUGH LOW LEVEL MIXING FOR STRATUS TO DEVELOP INSTEAD OF FOG...SO DECIDED TO LET EVENING SHIFT MONITOR TRENDS AND DECIDE IF FOG WORDING IS NEEDED. WITH THE THICK LOW LEVEL MOISTURE...DECIDED TO TREND A FEW DEGREES ABOVE MOS CONSENSUS FOR OVERNIGHT LOWS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... BRIEF UPPER RIDGING WILL MOVE OVERHEAD ON TUESDAY...THOUGH ENOUGH LOW LEVEL MOISTURE SHOULD STAY BEHIND TO KEEP SKIES PARTLY TO MOSTLY CLOUDY. DEEPENING SHORTWAVE DIGGING INTO THE MIDWEST WILL LEAD TO CYCLOGENESIS OVER NORTHERN ILLINOIS TUESDAY NIGHT. SFC LOW WILL TRACK INTO WESTERN MICHIGAN BY 12Z WEDS AND WILL PUSH A WEAK FRONTAL BOUNDARY ACROSS THE CWA WEDS MORNING. NAM CONTINUES TO BE THE SLOW OUTLIER WITH THE TIMING OF THIS SYSTEM...SO TRENDED TOWARD A GFS/ECMWF BLEND WHICH ARE IN REASONABLE AGREEMENT. WEAK ISENTROPIC LIFT WILL SPREAD IN AHEAD OF THE FRONT WEDS NIGHT...SO KEPT CHANCE POPS GOING AREA WIDE TUES NIGHT AND EARLY WEDS...WITH HIGHEST POPS ACROSS THE NORTH IN CLOSER PROXIMITY TO BEST UPPER LEVEL FORCING. LINGERING ELEVATED ISENTROPIC LIFT MAY PRODUCE A FEW LIGHT SHOWERS BEHIND THE FRONT WEDS EVENING. DEEPER SYSTEM WILL DIG INTO THE MIDWEST WEDS NIGHT WITH ANOTHER WEAK FRONT PUSHING INTO THE CWA BY 12Z THURS. THIS SYSTEM WILL BE MORE MOISTURE STARVED...SO KEPT POPS LIMITED TO LOW-END CHANCE THROUGH 12Z THURS. && .LONG TERM /THURSDAY THROUGH MONDAY/... LONG RANGE MODELS ARE FAIRLY SIMILAR IN TERMS OF SYNOPTIC POSITIONS THROUGH AT LEAST SUNDAY. HAVE MAINLY RELIED ON A 00Z/12Z GFS BLEND THROUGH THIS PERIOD. MODELS CONTINUE TO DEPICT A DIGGING UPR LVL CLOSED LOW WHICH IS FORECAST TO DROP FROM THE NRN PLAINS TO THE WESTERN GREAT LAKES BY THURSDAY. THIS FEATURE WILL PUSH ANOTHER COLD FRONT THROUGH THE REGION THURSDAY MORNING. WILL MAINTAIN A 30 TO 50 PERCENT CHANCE FOR SHOWERS. FOR THE PERIOD THURSDAY NIGHT INTO FRIDAY...AS THE UPR LVL CLOSED LOW CONTINUES TO TREK EAST TOWARD THE EASTERN GREAT LAKES...IT WILL UNDERGO SOME DEEPENING. THIS WILL ALLOW THE ATMOSPHERE TO COOL AS WELL AS ADVECT COLDER AIR INTO OUR REGION. WRAP AROUND/LAKE INDUCED RAIN SHOWERS WILL MIX WITH SNOW SHOWERS THURSDAY NIGHT...BECOMING ALL SNOW SHOWERS BY FRIDAY MORNING. SOME DIURNAL HEATING ON FRIDAY WILL ALLOW THE SNOW TO MIX WITH OR CHANGE BACK TO RAIN DURING FRIDAY AFTN. PCPN WILL TAPER OFF FRIDAY NIGHT. SHOWERS THURSDAY NIGHT INTO FRIDAY NIGHT WILL BE SCATTERED AND LIGHT IN NATURE. ANY SNOW THAT FALLS WILL HAVE A HARD TIME ACCUMULATING DUE TO THE LIGHT NATURE OF THE SHOWERS AND A FAIRLY WARM GROUND FOR LATE NOVEMBER. LITTLE TO NO SNOW ACCUMULATION IS EXPECTED ATTM. AFOREMENTIONED DEEPENING UPR LVL CLOSED LOW IS FORECAST TO PIVOT NE INTO THE NEW ENGLAND REGION BY SATURDAY. THIS WILL ALLOW HIGH PRESSURE AT THE SFC AND ALOFT TO BUILD INTO THE GREAT LAKES AND OHIO VALLEY FROM THE WEST. HIGH PRESSURE WILL MOVE EAST OF THE REGION ON SUNDAY...ALLOWING A COLD FRONT TO DROP FROM THE NW TOWARD OUR AREA LATE IN THE DAY. FOR MONDAY...HAVE KEPT CONTINUITY BY ALLOWING THE COLD FRONT TO SLOWLY DROP SOUTH OF THE OHIO RIVER. LATEST OPERATIONAL MODELS ARE STILL UNCERTAIN ABOUT THE WEATHER PATTERN INTO NEXT WEEK AS DEPICTED BY THEIR RUN TO RUN INCONSISTENCY. HIGH TEMPERATURES WILL FALL TO BELOW NORMAL READINGS THURSDAY AND FRIDAY WITH A RECOVERY TO NEAR NORMAL TEMPERATURES OVER THE WEEKEND. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... H5 S/W PUSHING THRU THE FA IS ALSO PUSHING THE MID AND HIGH LEVELS CLOUDS ASSOCIATED WITH IT OUT OF THE AREA. AREA OF CLEARING HAS WORKED INTO THE SE IN/SW OH/NRN KY. EXPECT THIS DEEPER MOISTURE TO PUSH NE OF THE TAFS BY 04Z. LOW LEVELS REMAIN VERY MOIST. EXPECT ST TO EITHER FORM OR MOVE N FROM KY AROUND 04Z. CIGS ARE EXPECTED TO LOWER IN MVFR RANGE. EXPECT SOME SCT IFR BR ALSO. MODELS ARE INDICATING THAT MIXING WILL OCCUR AFT 14Z AND THAT CIGS AND VSBYS SHOULD BECOME VFR BY LATE MORNING. OUTLOOK...MVFR CIGS/VSBYS POSSIBLE TUESDAY NIGHT INTO FRIDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HAWBLITZEL NEAR TERM...HAWBLITZEL SHORT TERM...HAWBLITZEL LONG TERM...HICKMAN AVIATION...SITES